Novel opioid-neurotensin-based hybrid peptide with spinal long-lasting antinociceptive activity and a propensity to delay tolerance development

The behavioral responses exerted by spinal administration of the opioid-neurotensin hybrid peptide, PK23, were studied in adult male rats. The antinociceptive effect upon exposure to a thermal stimulus, as well as tolerance development, was assessed in an acute pain model. The PK23 chimera at a dose of 10 nmol/rat produced a potent pain-relieving effect, especially after its intrathecal administration. Compared with intrathecal morphine, this novel compound was found to possess a favourable side effect profile characterized by a reduced scratch reflex, delayed development of analgesic tolerance or an absence of motor impairments when given in the same manner, though some animals died following barrel rotation as a result of its i.c.v. administration (in particular at doses higher than 10 nmol/rat). Nonetheless, these results suggest the potential use of hybrid compounds encompassing both opioid and neurotensin structural fragments in pain management. This highlights the enormous potential of synthetic neurotensin analogues as promising future analgesics.

Hyponatremia effect in patients with alcohol dependence on their physical and mental health status.

Hyponatremia, i.e. reduction of sodium level in the blood plasma below 135 mmol/L, is one of the most common electrolyte disorders occurring in people addicted to alcohol. Numerous psychopathological symptoms may be significantly associated with its occurrence. Since sodium is one of the main bioelements, which is responsible for proper neuromuscular excitability maintenance and contributes in nerve impulses conduction, sodium balance disorders may be related to a risk to basic life functions. The tested group included 100 alcohol dependent patients (M = 90, F = 10). Sodium was determined using biochemical Indiko Plus analyzer. Analysis of sodium concentration demonstrated that 64% of people with alcohol dependence had low (<135 mmol/L) plasma sodium level, of which: 7% had severe hyponatremia (<120 mmol/L), 13% had moderate hyponatremia (120-130 mmol/L) and 44% had mild hyponatremia (130-135 mmol/L). The analysis showed an occurrence of significant differences in terms of: impulsivity, quality of life, clinical symptoms occurrence, maximum amount of alcohol consumed and general health state. The lower concentration of sodium in blood plasma in alcohol dependent people, the worse psychical and psychological quality of their life.